At 6 p.m. PDT on Wednesday, the Pac-12 Conference will turn on its much-anticipated television networks and instantaneously transform the viewing experience for fans of a league that has long wallowed in the broadcasting shadows.

SAN FRANCISCO — At 6 p.m. PDT on Wednesday, the Pac-12 Conference will turn on its much-anticipated television networks and instantaneously transform the viewing experience for fans of a league that has long wallowed in the broadcasting shadows.

Based in San Francisco, the networks will ensure that all Pac-12 football and men’s basketball games are broadcast live and provide unprecedented exposure for the league’s world-class Olympic sports.

Four major cable companies, including Comcast in the Bay Area, are among dozens of providers that have agreed to air the networks, which consist of one national feed and six regional feeds — one for each area of the conference.

“We’ve got great content and great distribution with some of the most powerful companies,” said Gary Stevenson, the president of Pac-12 Enterprises, which oversees the television networks. “Those are two big checks.”

The Pac-12 isn’t the first college conference to have a dedicated television network. The Big Ten’s version went live in 2007 and has been a resounding success. Co-owned by Fox, it reportedly distributes approximately $8 million per year to its schools.

But the Pac-12 Networks, with their seven feeds, are unprecedented in scope, complexity and control of the content:

— The Big Ten Network had 20 million subscribers at launch. The Pac-12 won’t release its total but has already signed carriage agreements with cable companies capable of reaching 48 million homes.

— The Pac-12 Networks are wholly owned by the conference, creating the possibility for a huge financial windfall down the road.

Industry sources estimate the networks could distribute $10 million per year per school in a few years, when distribution and advertising are fully ramped.

— The Pac-12 Networks will air 850 live events during the 2012-13 school year, including Stanford’s football opener against San Jose State and Cal’s mid-September showdown against USC.

Every football and men’s basketball game not broadcast by ESPN or Fox will be shown live on the Pac-12 Networks — with all but a handful beamed nationally.

“It’s going to be awesome,” Stanford football coach David Shaw said. “We’ve been fortunate the last couple years to have a lot of national games. Now every game will be national. Recruits will be able to see every game.”

At this point, the Pac-12 Networks don’t have carriage agreements with either of the major satellite operators, DirecTV or Dish Network. But negotiations are ongoing, and commissioner Larry Scott is optimistic a deal will be struck with at least one of the satellite carriers.

Media industry sources believe DirecTV, with its reliance on sports programming, is far more likely than Dish to come to terms.

“We’ve got quantity and quality,” Scott said. “We wanted the networks to have premium content, and we had a clear view of how to attain that.”

Scott didn’t plan to create a dedicated television network when he took charge of the conference in 2009. But he eventually became convinced it would be the best way to increase exposure for Olympic sport athletes and to serve fans frustrated by holes in the league’s long-standing TV deals. (Last year alone, five Pac-12 football games and 90 men’s basketball games weren’t televised anywhere.)

Scott’s masterstroke came in the spring of 2011, when the league signed long-term deals with ESPN and Fox. In addition to collecting $3 billion — it was the richest TV deal ever signed by a college conference — Scott retained the rights to 35 football games, thereby guaranteeing in-demand content for the not-yet-announced network.

He dangled that content in front of Comcast, Time Warner Cable, Cox and Bright House and got them to partner on the Pac-12 Networks. Then Scott used the up-front cash received from the league’s media deals to fund the startup costs of the networks, believed to be between $50 million and $100 million.

The schools weren’t on the hook for a dime.

“The networks will be self-supporting,” Scott said.

And because of the financial cushion provided by the ESPN and Fox deals — each Pac-12 school will receive an average of $21 million per year for 12 years — the conference could create the networks it wanted, not the networks it needed.